Active Autowerke GESI Catted Downpipes – BMW X3M / X4M (F97 / F98, S58)

OVERVIEW

BMW's valvetronic direct-injection engine family evolved into the twin-turbo S58 used in the M-series cars, whose factory downpipes are a bit restrictive and slow exhaust flow and turbo spool. The Active Autowerke X3 M / X4 M Signature downpipes use 3 inch diameter stainless steel piping with stainless flex joints and a step down to 70 mm to meet the OEM exhaust system — never dropping below the stock 70 mm — for more power, quicker spool and extreme durability. This variant includes a pair of 4.5 inch high-flow GESi G-Sport Ultra High Output catalytic converters built in full 304 stainless including the substrate, whose proprietary precious metal loading keeps emissions low at high flow so no check engine light or failed emissions test results.

SPECS

• 3 inch diameter stainless steel piping, stepping down to 70 mm at the OEM exhaust connection
• Diameter is never reduced below the stock 70 mm
• Pair of 4.50 inch ultra high flow GESi G-Sport catalytic converters, 400 cells per square inch
• Rated for 500 to 850 hp applications
• TIG welded 304 stainless steel construction throughout
• 304 stainless steel catalyst substrate, furnace brazed to the mantle for durability
• Cast upper stainless steel V-band for precise fitment
• Stainless flex joints
• Withstands temperatures up to 1500 F
• Reaches operational efficiency within 9 seconds of startup
• EPA registered, fully OBD2 compliant for 1996 and newer vehicles, except in California
• Suited to forced induction applications with no loss of horsepower
• Bolts on with no cutting or welding required
• Made in Miami, Florida
• Covered by a 5 year / 50,000 mile warranty on the catalytic converter

PARTS INCLUDED

• Pair of downpipes with GESi catalytic converters, as supplied by Active Autowerke; see the installation instructions for the full bill of materials.

TECH RESOURCES

Additional Parts Required

• None. Active Autowerke specifies no additional hardware for these downpipes; they bolt on with no cutting or welding required.
• Installer supplies basic hand tools and a lift or jack stands.

Installation

• Active Autowerke catalytic converter break-in instructions (PDF) — follow this procedure on first start-up to avoid a check engine light being set in error
• Active Autowerke installation instruction library

Notes

• Please note: These catalytic converters are not legal for use on vehicles registered in the state of California as a result of California Vehicle Code Sections 27156 and 38391.
• Note: Federal law prohibits the tampering of an emissions control device. Mobile Source Enforcement Memorandum 1A allows for aftermarket parts to be used in the repair or replacement of emissions control systems, provided the emissions aren't adversely affected. There is no mention or reference to cell density or converter volume dimension. The GESi catalytic converter will produce emissions that meet or exceed the standards set by the EPA, not CARB.
• Fits S58-engined X3 M and X4 M only. Fitment applies to US-model cars only; Active Autowerke cannot guarantee fitment to non-US model cars. Confirm fitment with Speed Logic before ordering.

PART NUMBER

• 11-070

VEHICLE APPLICATIONS